Was the 1972 reversion of Okinawa to Japanese sovereignty from the United States fairly carried out, or did the government flub its accountability?
This has been questioned for more than 35 years by historians, lawmakers and journalists as suspicions linger that there was a secret agreement over Japan's assumption of the reversion costs so Tokyo could smoothly carry forward the negotiations without drawing opposition.
A new probe into the background of the suspected secret accord will be begin early next month when a group of professionals will request government disclosure of pertinent documents.